Microsoft, SCO brace for MyDoom blitz

If the denial-of-service "bomb" within the MyDoom virus now flooding email channels is detonated today, as planned, the websites operated by Microsoft and the SCO Group, a small software company in Utah, can each expect to be hit by 1.5 million emails a second.

Both companies are targets of such denial-of-service "bombs". "We estimate about 500,000 computers around the world now have MyDoom active in their system and each of them will generate three emails a second," said Alan Bell, of Network Associates in Sydney.

Microsoft has offered a $US250,000 ($A328,601) reward for information leading to the arrest of the author of MyDoom, matching an earlier offer by the SCO Group. Neither Microsoft nor SCO is expected to suffer much damage. Each is likely to open an alternative website that visitors can reach via a link.

MyDoom has continued to proliferate and is rated by some anti-virus agencies as rivalling SoBig, the worst virus recorded, estimated to have caused a $US37 billion loss in productivity.

Meanwhile, anti-virus engineers are concerned about another virus, MiMail-S.

"If you see a message such as 'Hi! Here is the file you asked for!' in an email that has a .txt.scr attachment, do not open it," he warned. Mr Bell said MiMail traffic had increased and its risk rating raised from low to medium. "We are concerned that infections will increase over the weekend."

Mr Bell said serious virus attacks seemed to be increasing.

"Last year, with Blaster, Nachi and SoBig, we had three major outbreaks," he said. "At the beginning of 2004, we had Bagle last week, MyDoom going crazy this week and now MiMail."

Members of the Linux community have reacted angrily to suggestions that one of their number could be using MyDoom to attack SCO. The software company has upset Linux developers by suing IBM, accusing it of using Unix code it owns in a version of Linux it supplies.